Certain kinds of vacuum bag tooling employ large tooling surfaces upon which composite materials are placed and covered by a sheet of airtight bagging material. The sheet is sealed to the tooling surface around the outer boundary of the composite, thus providing an airtight space in which the composite is received. As would be familiar to a person skilled in the art, this space is evacuated which causes air pressure acting on the sheet's outer surface to force both the sheet and composite against the tooling surface, after which the composite is cured.
One method of sealing the sheet is to use a triangular pyramid sell made of silicon which is bonded to and protrudes upwardly from the tooling surface. Unfortunately, this type of seal is known to be easily damaged during part layup and removal. For example, shop personnel placing uncured composite materials onto the tooling surface and removing cured parts thereafter must exercise great care in avoiding composite contact with the seal. Carelessness in doing this can quickly damage the seal necessitating its repair or replacement. In an automated production environment this means costly down time. Still further, on large tooling surfaces the sheet must be momentarily held down on the seal prior to evacuation in order to ensure good seal engagement with the sheet. This can be time consuming and is also undesirable in an automated environment. As will become apparent, the present invention provides an improvement over these drawbacks.